Process of purifying oils.



UNITED STATES ATENT OFFICE.

WALTER O. SN$ LLING, 0 1? PITTSBURGH, PENNSYLVANIA, ASE IGNOR OF FIFTY-ONE ONE-HUNDREDTHS TO JOHN T. MILLIICEN, OF ST. LOUIS, MISSOURI.

PROCESS OF PURIFYIN G OILS.

Specification'of Letters Patent.

' 1Y0 Drawing.

To all whom it may concern: Be it known that I, WALTER O. SNELLI-NG, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Processes ofPurifying Oils, of which the following is a specification.

This invention relates to processes of purifying oils; and it comprises a process of removing sulfur from oils wherein crude oils, or distillates therefrom, containing sul-.

fur are heated or distilled in the presence of cracked h drocarbons-having-an afiinity for sulfur; a l as more fully hereinafter set forth and as claimed. I Many crude petroleums contain sulfur and this sulfur is apt to occur in volatilizable compoundswhich will distil over with distillates, contaminating the same and rendering necessary the use of expensive purifyin treatments. The presence. of sulfur in suc products as gasolene or kerosene is highly undesirable for many reasons. The, form in which the sulfur occurs in these oils is not definitely known. but it appears to occur as What is sometimes known as sulfid sulfur; in a state of combination analogous to its state of combination in such compounds as ethyl sulfid. Very many ways .of removing the sulfur have been proposed,

such as the use of copper oxid, lead compounds, etc but these methods all require 'the use of chemicals which are expensive, or which necessitate an expensive regeneration; or both.

.I have found however that this sulfur occurrin in this state of combination may be readi y transferred from one h drocarbon to another; and that it'slten ency to unite to and firmness ofpombination with,

heavy hydrocarbons is greate than its tend ency to unite. to,-and firmness'of combination with, lightbhhydrocarbons. This enables me, so memes transfer. the sulfur from the morevialuable li ht and relatively volatile "hydrocarbons fsuc as gasolene and kerosene to the less valuable heavy and relativelydess volatile hydrocarbons. I have found, for example, that by heating a gasp lene or a kerosene containing sulfur together with a heavy cracked oil ofhigh boiling fpoint, the'sulfur is transferred from the gasolene or from the kerosene,'to"the heavy Patunted Feb. 13, 1917.

Application fil ed Apr-11.8, 1915. Y Serial No. 19,864.

hydrocarbon, and the gasolene or kerosene, can then be easily so arated from the sulfurcontaining high'boilng oil by simple distillation. The distillate so obtained is-free, or substantially free, fr 3m sulfur. The theory of this reaction ap cars to be that the sulfur has greater a rity for the more comp'lex heavy hydrocarbons than it has for the lighter, less complex hydrocarbons, so that in the heating operation it passes from the one to the other. The same treatment maybe appliedto a crude oil, as by mixing a sulfur-containing crude oil with a heavy cracked hydrocarbor of, say, the boilin point of gas oil, solar oil, lubricating oi wax oil' and performing the distillation in the usual manner. Cracked or tarry still residues which are'rot valuable except for fuel may be used for theipresent purposes. The gasolene or kerosene components of the crude oil will distil over substantially free of sulfur. The sulfur remains in the residual high boiling-oil, whence it may be removed; or the residual high boiling oil may be used for fuel orother purposes where the presence of sulfur is unimportant. Or the residual oil containing the sulfur may be submitted to a cracking distillation to givecracked gasolenc and cracked kerosene. Thecracked residue Ls capable of absorbing stilll more sulfur from another portion of 01 The power of abstracting sulfur from the natural sulfur compounds in crude petro- .a boiling point above.500 F,1,;. mey beobtained in any convenient mama, as by usln the residue from an ordinary crackin istillat ion. But it is better-to make the su fur-absorbing material in a s ecial way, as [by cracking 'un ler redu pressure; For. example, oil oil vapors may be led M roduct through a pyrolyzing zone, such as a hot tube, under reduced pressure. For example, crudepetroleum, gas-oil, etc., may be transmitted through a tube heated to, say, 500 "to600 F. and thence through a cooler 'or condenser. This results in a liquid containing cracked gasolene or cracked kerosene, and cracked high boiling oils. On distillation of thisproduct, the gasolene will come'over substantially freeqof. sulfur;-.the.sulfur if any be present, remaining with the. high boiling-residue in the still.

This cracked high boiling residue may next-be mixed withcrude petroleum, of the same or another kind and} distillation resorted to in the usual manner until the gasolene and kerosene are distilled ofi. The dis-- tillation 'may be carried further to form high'bo'iling lubricating oil, such' as spindle oil, the grades known as solvent oils, etc.

The residue in the still may next be sub-' mitted to' a cracking operation and the prod: not obtained used as before.

I Or, and advantageously, gasolene or kerosene or spindle oil may be redistilledin the ordinary way after admixing with the high .bo ilin% cracked. oil and heating together.

This ating' may be under a reflux con.

denser for a, time in'the ca s e'..of oils-whose sulfur is diflicult to transfer; or it may be vheating merely in the manner incident to redistilling and-regaining "the gasolene or kerosene which has been mixed with the high boiling oil. Heating the two oils (the cracked oil and the oil from 'which'sulfur is to be abstracted) may be advantageously performed under pressure.

' been used in-any of these ways and is,isoto 40 lunderthe boilers or 'stillsonis sent. into Ordinarily the high boiling oilwhich has speak, saturated with sulfur is finally burned 7 the marketasfueloil."

What I claim is: p

1. The process of removing sulfur from hydrocarbon oils which comprises heating a sulfur containing oil in the presence of a cracked oil capable of absorbing sulfur.

- 2. The process of removing sulfur .from hydrocarbon oils which comprises distilling such an oil in the presence ofaflheavy cracked oil capable of absorbing sulfur.

- 3. Theprocess of removing sulfur fromlow boiling petroleum oils which comprises heating'sucha low boilingoil in the presence of a heavy cracked oil capable of absorbing sulfur. v g.

4. The .process of removing .sulfur from low boiling petroleumoils which comprises distilling such-a low boiling oil in the pres-. ence of a'heavy cracked oil capableof-absorbing sulfur. i v

- 5. The process of removing sulfur fromlow boiling petroleum oils which comprises mixing a crude petroleum with a cracked high boiling oil capable of absorbing sulfur and heating themtogether.

6. The process of removing sulfur from low boiling petroleum oils which comprises mixing a crude petroleum with a cracked :high boiling oil-capable of absorbing sulfur and then distilling .ofi the low boiling oils.

7. The process of removing sulfur from low boiling petroleum oils which comprises mixing a crude. petroleum witha cracked high boiling oil capable of absorbing sulfur heating this mixtureunder pressure, to

facilitate interchange of the sulfur from the low boiling hydrocarbons to the cracked,

high boilingjoils, d then distilling fi the low boiling oils.

In. testimony. whereof, my signa- WALTER IS'NE N i; 

